iPhone 12 battery draining fast

That really doesn't look fixed at all - that's the same sort of drain that most of us have been complaining about! Even in low-power mode overnight, you've still lost a good 10-15% of battery life. So that still looks broken to me - if that's "fixed" for you, then I dread to think what your drain was like before...

Of course they didn't lol. Think it's going to be one of those silent fixes that they pretend never happened aha. But there is hope...like I said...first night in forever that the drain was finally similar to that of the 11 Pro Max. Too early to jump for joy though as only tested one night so I will report back tomorrow.

I have drain on dual sim but not on eSim.

But it’s not as simple as just switching off one line. To stop the drain I have to force restart the phone each time I turn off the second line, otherwise it keeps draining even on a single eSim line.

I thought i'm gone mad, but maybe there is someone like me. I had usually from 15 to 20% battery drain on idle, but the last 2 days there is around 2 to 4% battery drain. It might that they have changed something silent and they will pretend that nothing was happened..

A lot of people posting 3G as a solution do not realise that for a lot of us 3G option is not even available. Only 4G and 5G. It just depends on the operator.

But the issue is with modern, most likely software/firmware because reset/restart can help sometimes.

We have to wait for Apple to fix this. Unfortunately, memory leaks aren’t easy to reproduce and fix, and this could be one of those cases unfortunately 🤷‍♂️

Could this be the network settings reset effect which might happen as a part of os update? Did you notice any temporary improvement after each system update to have the issue come back shortly afterwards?

Yes, it will reset the modem hardware. It looks to me as if what is happening is that the modem at some point goes into a high-power state (which is in itself not unusual - transmitting requires high power), but instead of dropping back to the idle state afterwards, it locks up in the high-power state, causing battery drain. If you restart the phone, you put the modem back into the normal mode of operation and the lock-up is temporarily fixed, until whatever causes the lock-up is triggered again.

Another point guys

for those who have the issue in dual sim mode, have you noted if the drain is the same whatever the line on which the cellular (4g-5g, ....) is active? I noted that it happens only when cellular is activated on the e-sim line...another guy from China has likely the same issue as me....

https://discussions.apple.com/thread/252133060?login=true

Thanks

I honestly don’t believe this to be a software issue, at least not a bug that can be fixed properly with a software update.

I think it’s amazing what Apple can do to optimise their OS and software to use as little power as possible. However, I honestly think that Apple have been a little too optimistic this year. They’ve overestimated how much software, combined with the A14 5nm can do with regards to power management. If Apple had of kept battery capacity’s at the same level as last year, added to the A14 5nm chip and software optimisations power efficiency would have been much better.

with that said, I believe this battery drain issue to be a problem with the modem it’s self. Look at Android phones with the same modem (The Qualcomm X55 I believe it is) they’ve all had similar issues. The modem used in the iPhone 12 series is known to be less power efficient than other modems available. Apple are switching to the Qualcomm X60 (I may have the model names slightly off) next year for the iPhone 13 series, which, is a much more power efficient, and all around more capable modem than the one they’re using this year.

sadly, I honestly don’t think we will see a real fix for this until the third quarter of 2021. Apple will already be aware that battery drain is a real concern on the 12 series, so, they will need time to either make replace models and start a replacement programme, or, release a statement informing iPhone 12 series owners to take their devices into their local Apple stores to be repaired there and then. I’d guess that the first scenario is more likely. Sadly I can’t see this issue being fixed with a software update, no matter how much Apple may try. I’m not even going to contact Apple support because, for me, personally I’ve two choices A. Return my device or B. Hold off and wait for the inevitable recall later on in 2021. If this issue is widespread enough Apple may indeed need to offer replacements with different modems, which offers its own problems because all future iOS updates for the iPhone 12 series may be fragmented due to differences in modems. If Apple do indeed go with a modem change and replace devices though I’d hope that they’d do this for all iPhone 12 series devices across the board.

I’m very happy with my iPhone 12 Pro Max, but power consumption does concern me. If I compare battery life on my 12 pro Max to my XS Max there really isn’t much difference at all. The 12 pro Max has ever so slightly better battery life than my XS Max, but not two generations of iPhone better. My partner had a regular iPhone 11 with an LCD display and her battery life puts my 12 pro Max to shame. Considering that my 12 pro Max has an OLED display that uses less power than regular LCD this doesn’t reflect well on the 12 pro Max at all. My 12 pro Max has acceptable battery life, but from a phone this big, with a 5nm chip, and all of apples software optimisations I’d expect a solid 2 days battery life for my personal usage. These are the settings I use on my 12 pro max:

5G is always turned off completely.

Background app refresh is always turned off.

Bluetooth is turned on for around 1 hour each day.

Location services are on for around 1 hour a day and then disabled as is mobile data.

I’m connected to WIFI all day and night.

Dark mode is permanently enabled and I use a dark wallpaper.

Automatic brightness is enabled.

with the above settings I’m getting through a day easily, but I’m disabling features that are essential really and listed along with the device as, well, features. If I turn background app refresh on, mobile data, Bluetooth and 5G my 12 pro Max can’t make it through the day.

one thing I’ve always enjoyed on iPhones and iPads is the standby time. Usually I can leave my iPhone on my bedside table at 100%, go to sleep and wake up 7 hours later with 100% battery life, or 99% worse case. My 12 Pro Max drains 15-20% whilst I’m a sleep for 7 hours with only WIFI enabled. I can get that to 10-15% with lower power mode enabled.

my 12 pro Max also seems to get too hot every few hours. A complete shutdown then power back up resolves the heat issue so perhaps the battery drain is being caused by the modem getting stuck in some kind of power loop.

anyway, I look forward to reading other people’s views and options on this issue and let’s hope there’s a fix on the way sooner rather than later.

My iPhone 12 is having same issue - definitely draining faster than my previous iPhone XS. Have tried all the stuff I have read about to remedy but problem persists. Apple please sort this out, you are getting a lot of investment from me and I expect value I have been used to.

Guys, I think I found the solution. When I got my iphone 12 pro brand new, I restored my backup from icloud. The battery was draining fast after I did that. I now reset all content and setting. The battery is doing very well. If you are having the same issue as I did, try this and it should solve it.

No, that has been tried previously by numerous people on here (including me), and it doesn't fix the problem; it is nothing to do with the contents of a previous backup.

This is a problem with the modem chipset in the 12 - it is either a hardware problem which will not be fixable, or it is a problem that Apple and Qualcomm may be able to fix with new modem firmware. Anything else people try - other than switching off the 4G and 5G capability of the modem - isn't going to make a difference.

You are wrong.

F.4 really improves everything, it behaves absolutely different in comparison with 14.3!

-2% per 8hours - 1st night

-3% per 10hrs -2nd.

I have fully charged my phone yesterday at a midday, now after 28 hours I have 59% of battery and 4 hours of SoT, and this period includes full 10hrs night with drain at 3%.

So this (f.4) significantly improves standby battery life. All of the Russian and Ukrainian users of our biggest russian community already pointed that the problem is solved.

nlnl88 wrote:

• I don't know if it's solely related to modem.

I tried many different configuration on 14.3, here are my results for a 7 to 9hr night:

Wifi on / BT on / dual SIM 4g ==> 30% lost

• Wifi on / Bt off / cellular data disabled + low power mode==> 20% lost

• Wifi off / BT off / 4g + low power mode ==> 10% lost

• Wifi off / BT off / 3g + low power mode ==> 10% lost

This is modem related.

Low power mode does not work correctly.

Be sure to try:

Wifi on / BT on / 3g ==> 0-5% lost

Wifi on / BT on / cellular data off ==> 0-1% lost

Simon Long wrote:

Mobile data controls whether or not the phone will use a pure data connection over the cellular modem. It doesn't prevent the phone using voice over the cellular modem. If mobile data is disabled but the phone is still using 4G for voice and for periodic handshaking communications with the network, then the power drain (which appears to be due to the use of 4G and 5G on the Qualcomm modem) will persist.

Switching off mobile data does not turn off all cellular activity from the phone, and so does not fix the power drain. So it is disabling 4G and 5G which fixes the problem, not disabling mobile data.

Thank you! An excellent and clear answer.

Now I finally understand why I need to switch to 3G before disconnecting cellular data.

If 4G is not turned off, the phone can use 4G for voice transmission.